Investigating the potential of a high altitude sleeping pill
by Ted Kincaid |
UAA biology professor Chris Jung has been a climber all his life. He is also a trained
sleep physiologist and chronobiologist. What do these subjects all have in common?
Apparently, melatonin.
"Melatonin is a hormone produced by the pineal gland in your brain," Jung, a doctorate
in integrative physiology and neuroscience, explains. "It acts as a sedative and helps
you sleep."
Melatonin is also a vasodilator (it causes your blood vessels to widen, thus decreasing
blood pressure) and an antioxidant, according to Jung. So he put all these pieces
together with his experience at high altitudes and asked the question: Could additional
melatonin help climbers adapt to extreme altitude better? And if they adapt better,
could that also help decrease the likelihood of cardiovascular and sleep problems
and decrements in cognition at elevation?
This summer, for three and a half weeks in May and June, Jung took a team of researchers
to Camp 14 on Denali to test his hypothesis. Camp 14 is named for its elevation of
14,200 feet. The Denali National Park Service rangers sent out emails to climbers
ahead of time who planned to be on the mountain during the research team's window.
In addition, a little bit of stormy weather helped them to recruit volunteers."I was very happy with how many people came to us to participate in the study," Jung
says. "We ended up getting about 30 consents signed, and after everything was said
and done we had 20 participants that we could use for the data."
Jung describes the field conditions, giving a big shout out to his climber-volunteers:
"Even in a lab where everything is prearranged, you still get data missing from equipment
failure, so you can imagine at subzero temperatures, we were at the mercy of batteries,
which don't work as well when it's cold, and so on. And climbing is hard enough as
it is-being in the cold; you're not sleeping as well at altitude-and then having this
equipment on you when you're sleeping and have to hang out in a tent and have your
blood pressure taken, it's just not the easiest of things. There were a lot of different
hurdles to jump over, but it was really nice that we did get so many volunteers."
Jung says that this is the first time that melatonin has been tested in this extreme
environment. At sea level, people do take melatonin as a sedative to help initiate
sleep and it's also been used for cancer treatment and jet lag. So melatonin pills
aren't new, but Jung's particular application is.
Jung's tests on Denali were set up as a double-blind, placebo-controlled study in
which each participant received two pills-one night a melatonin pill and the other
night a placebo. Nobody knew who got what pill which night, neither the volunteers
nor the researchers. Post-pill, the researchers measured sleep variables (how well
each participant slept each night, how fast they fell asleep, different stages of
sleep, etc.) as well as cardiovascular variables (heart rate, blood oxygen saturation
and blood pressure) and cognition."There is data that shows that people who spend long periods of time at extreme altitudes,
for example on Everest or K2, show differences in their brain physiology before and
after exposure to altitude," Jung explains. "And we know that this is because of oxidative
stress. Between the already depleted oxygen supply at altitude and not sleeping well,
it's a double whammy and has a dramatic effect on the neurology that's going on in
the brain."
Although the team is still crunching numbers to measure outcomes, Jung is excited
to see how this acute one-night test may lead to testing over a longer expedition,
a higher expedition and dosage over multiple nights. His team's results will act as
preliminary data for larger projects in the future.
In preparation for the "Sleep 2013" conference in Baltimore next summer, Jung expects
to have his research abstract and results ready to publish by December. His research
was made possible by a UAA Faculty Development Grant of $4,500 and a private grant
that came through the UA Foundation for $700. Their sleep monitoring equipment was
donated by Zeo Inc. and Jung collaborated with UAA's Department of Psychology to acquire
the necessary cognitive tests to use, in this case, the Stroop Test. Mountain Hardware
also helped the team out with a modest sponsorship.
Mostly, Jung is pleased by how well his research team worked together in the extreme
conditions on Denali as well. Not only did they help kick in to cover expedition costs,
they also split up tasks on the mountain for a smooth-running, professional operation.In addition to the research expedition team (pictured right), UAA undergraduates Shea
Lowery and Zach Worthington are helping Jung at sea level to process the data captured
on the mountain. UAA's Loren Buck, Ph.D. (biology), and Yasuhiro Ozuru, Ph.D. (psychology)
were collaborators on protocols, and Peter Hackett, M.D., from the University of Colorado
School of Medicine and the Institute of Altitude Medicine was the project's medical
monitor.
Keep an eye on Jung's CV for updates on the current melatonin research; results to be published in early 2013.
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